He also questioned her physical stamina and her mental health and said she has contempt for Americans.

"She has been a disaster. Here's a woman she's supposed to fight all these different things and she can't make it 15 feet to her car," he said gesturing a wobble. "Give me a break."

Trump supporters often chant, "Lock her up!" during his events. But Trump himself has avoided such language in the past.

The GOP candidate made the remarks during an appearance at Spooky Nook Sports, an indoor sports complex. He was nearly two hours late to the event telling the crowd of 5,801 there were concerns about landing his helicopter because of poor weather. The venue is about 84 miles west of Philadelphia.

Trump lobbed attacks at former president Bill Clinton's policies and marital infidelity suggesting that the former first lady isn't loyal to her husband.

"I don't even think she's loyal to Bill, you wanna know the truth. And really folks, really why should she be, right? Why should she be," he said with a chuckle.

He has been trailing or tied with Democratic challenger Hillary Clinton in national polling leading into their first debate at Hofstra University on Monday. The latest NBC News-SurveyMonkey online survey of likely voters put Clinton at 5 points above Trump.

Pennsylvania has been a key battleground state for both candidates leading up to the Nov. 8th election. Clinton will stump in Philadelphia and Harrisburg on Tuesday.

Trump also tried out a new strategy to attract Bernie Sanders supporters.

He highlighted a leaked audio recording of Hillary Clinton from a private fundraiser in February, when she was still running against Sanders in the Democratic primary. In the recording, Clinton says many young people who support Sanders are living in their parents' basements, unsatisfied with their education and jobs.

The Trump campaign thinks it can attract a significant number of Sanders' Democratic supporters who are unhappy with Clinton as their nominee.

Sanders has endorsed Clinton and campaigned with her earlier in the week.

The Times story centered around an analysis of Trump's 1995 tax returns, which had not previously been released publicly. The report said Trump could have used a $916 million loss to avoid paying taxes on income totaling the same amount. Citing tax experts, the paper said the candidate could have stretched out the loss for years, and thus avoided paying income to the federal government.

Trump's campaign issued a statement shortly after the story was published, not denying the assertions, but rather saying the candidate has paid other taxes in the past and "no more tax than legally required."

"Mr. Trump has paid hundreds of millions of dollars in property taxes, sales and excise taxes, real estate taxes, city taxes, state taxes, employee taxes and federal taxes, along with very substantial charitable contributions," the campaign said in a statement.